The present invention relates to a golf club, and more particularly to a golf club having a head with selectively placed weighting elements, and the method for applying such weighting elements.
The ideal swing of a golf club results in the striking face of the golf club head meeting the golf ball at the center of mass of the golf club head. This location on the golf club head is known in golfing parlance as the "sweet-spot". Striking the golf ball at a location away from the center creates a turning force which tends to rotate or twist the golf club head. This rotation imparts side spin on the ball which causes irregular ball flight. This rotation also reduces the energy transferred to the golf ball, and may negatively influence the intended direction and length of flight or roll.
Many efforts have been made to improve the performance characteristics of a golf club when striking a golf ball away from the center or off-center. A very well known method involves increasing the moment of inertia of the golf club head. The moment of inertia corresponds to or indicates the resistance a system offers to a force which is acting on it in order to set it in motion. The moment of inertia is a function of the mass of each individual particle in a system multiplied by the distance squared between the particular particle and a selected axis through the system. For a golf club head, the relevant axis is drawn through the center of mass of the golf club head.
U.S. Pat. No. 3,941,390 to Hussey teaches adding weighting elements along the outer perimeter of the golf club head in order to maximize the distance between this added mass and the relevant axis. This arrangement tends to improve off-center hits of a golf club such that there is less rotation of the golf club head than would otherwise occur. These added weighting elements, however, by being placed on the outer perimeter of the golf club head do not lie behind the striking face of the golf club head.
The prior art teaches a variety of methods for affixing weighting elements to golf club heads. U.S. Pat. No. 3,356,782 to Whyte teaches pouring a hardenable liquid into a pre-formed cavity in a golf club head. U.S. Pat. No. 3,556,533 teaches using fastening screws of different weights for attaching a sole plate to the bottom portion of a golf club head. U.S. Pat. No. 3,941,390 to Hussey teaches attaching weighting materials by either screws, an adhesive, or by dovetailing the weighting material into a formed cutout. Each of these methods of affixing the weighting materials have several drawbacks. These methods are time consuming, clumsy and subject to failure over the course of time.
Accordingly, it is an object of the present invention to provide a golf club in which the negative effects of off-center strikes is minimized.
Another object is to provide a golf club head with an increased moment of inertia.
Another object is to provide a golf club head with an increased moment of inertia through the addition of weighting elements toward the rear or trailing edge of the golf club head, and located behind the outer limit of possible off-center toe and heel hits.
Another object is to provide a golf club head with an increased moment of inertia through the addition of weighting elements toward the rear or trailing edge of the golf club head, and located behind the outer limit of possible off-center toe and heel hits, and such that the center of gravity of the golf club head is moved toward the rear or trailing edge of the club.
Another object is to provide a method for more easily and more securely affixing weighting elements to a golf club head.
Another object is to provide a method for more easily and more securely affixing weighting elements to a golf club head by spraying the weighting elements into indentations in the golf club head.